Racism is an incendiary word. It should be used carefully and cautiously. But when racism does appear, it should be identified and indicted.

That brings up two questions: Are Democrats correct in saying that Republican opposition to immigration reform is fueled partly by racism? Are they playing the race card for political reasons?

The answer to both questions is yes.

This debate was ignited by Nancy Pelosi, the former speaker of the house, who said recently of House Republican leaders: "I think race has something to do with the fact that they're not bringing up an immigration bill. I've heard them say to the Irish, if it were just you, this would be easy."

Asked about Pelosi's comments on CNN, Rep. Steve Israel, one of her lieutenants, replied, "To a significant extent, the Republican base does have elements that are animated by racism."

Host Candy Crowley retorted that Israel's comment "looks very much like election-year strategy, trying to get your base out." She has a point.

Democrats are verging on panic. They have no chance of recapturing the House in November and could well lose their six-seat margin in the Senate. Enthusiasm is all on the Republican side, with 81 percent of GOPers telling CBS they will definitely vote in the fall; only 68 percent of Democrats say the same.

As President Obama put it last month, Democrats "get clobbered" in midterm elections because they have trouble turning out key constituents, including young people, women, blacks and Hispanics.

That's why party leaders are focusing on economic issues like the minimum wage and pay equity for women. And that's why they're bringing up race. They want their voters angry and energized.

But just because the Democrats have political motives does not mean they are wrong. In fact, the evidence shows that they are right.

Let's be clear: In no way are we saying that all Republicans are racists; nor are we saying that racism is their only motive for opposing immigration reform. But racism does help explain why the party's hard-core base has blocked any action on immigration reform in the House, even though a bipartisan bill easily passed the Senate.

Some of those opponents don't even try to hide their feelings. Take Rep. Steve King of Iowa, who said of young immigrants, "For every one who's a valedictorian, there's another 100 out there who weigh 130 pounds and they've got calves the size of cantaloupes because they're hauling 75 pounds of marijuana across the desert."

More often, racism simmers below the surface. The website Buzzfeed recently quoted a "Southern Republican lawmaker" on this very point: "Part of it, I think - and I hate to say this, because these are my people - but ... it's racial. If you go to town halls people say things like, 'These people have different cultural customs than we do.' And that's code for race."

Page 2 of 2 - Of course it is. We all know it is. And that code has been used since the beginning of the country. Sen. Lindsay Graham, a South Carolina Republican who supported the Senate reform bill, said: "We have a history in this country of demagoguery when it comes (to immigration) ... There's nothing new going on today ... This isn't the first time there's been some ugliness around the issue of immigration."

When Steve wrote a book on immigration, "From Every End of This Earth," he researched the history, and Graham is completely correct. Each new wave of immigrants elicits the same response: This group is "different"; they will degrade our culture and debase our character.

In 1753, Ben Franklin called the Germans flocking to Pennsylvania "generally the most stupid sort of their own nation" and warned: "They will soon outnumber us (and we) will not, in my opinion be able to preserve our language, and even our government will be precarious."

In the mid-19th century, a Chicago newspaper wrote, "Scratch a convict or a pauper and chances are you tickle the skin of an Irish-Catholic." In 1891, 11 Italians were lynched in New Orleans, and a newspaper described the victims as having "low receding foreheads, dark skin (and) repulsive countenances." In the 1940s, more than 100,000 loyal Japanese-Americans were forced into internment camps.

These groups did not diminish the American culture; they enhanced it. We are a richer nation because they came, and the same holds true for Hispanics today. Sure, the Democrats are playing politics, but two facts remain indisputable: The racists are real. And the racists are wrong.

Steve and Cokie Roberts can be contacted by email at stevecokie@gmail.com.